This invention generally relates to an apparatus for positioning a web of paper stationery with respect to the print mechanism of a high speed printer and more particularly relates to such an apparatus which includes means for accommodating various web widths and for positioning the web so as to accurately locate the printed type margin thereon.
The rapid growth of data communications systems, over the last few years, has greatly increased the demand for high speed alphanumeric printers which print the informational data in readable form upon a paper web. Such printers are frequently operated on a continuous basis and require operator attendance only for replacement of an exhausted paper supply or clearance of a paper jam. The paper stationery used in such printers is generally supplied as a continuous sheet with transverse perforations facilitating the removal of selected pages. Additionally, extending longitudinally adjacent the margins of the paper are a series of spaced sprocket holes which are engaged by a drive mechanism provided on the printer which drives the paper past the print mechanism.
A wide variety of stationery sizes are available having various widths to accomodate different user requirements. Thus, for greatest versatility, it is desirable that the printer include means for adapting to a wide range of paper widths. Frequently, during daily operation, the operator is required to change the paper in a printer to one having a different width to correspond with a new data format. Additionally, the location of the print margin on the paper may require a corresponding adjustment. Often, one operator is assigned the task of servicing several machines and thus it is extremely important that the printers under his supervision be adapted to facilitate rapid and convenient replacement of the paper therein and adjustment to varying paper size and data format. One such device adapted for positioning the paper in a teleprinter is described in U.S. Pat. No. 3,799,313 entitled "Adjustable Sprocket Assembly" issued to B. L. Shevick on Mar. 26, 1974, having a common assignee with this application. As described in this reference, the sprocket drives are independently positioned to accommodate the paper width. Margin adjustment of the type upon the paper necessitates repositioning both of the sprocket drives and is a somewhat cumbersome procedure. J. M. Ostray in U.S. Pat. No. 1,938,531, entitled "Adjustable Guide for Paper Plates of Typewriters" describes a device which includes two slides for engaging the margins of the paper. The paper is positioned at the desired location and each slide positioned until the paper nests between them. Once positioned, it is relatively difficult to reposition the paper to varying the location of the print margin thereon since; to accomplish this end, both of the slides must be repositioned. U.S. Pat. No. 2,273,565 issued to J. E. Euth et al. on Feb. 17, 1947 and entitled "Stationery-Guide Assembly" is addressed to this problem and provides two paper margin guides supported upon a support screw. The guides are positioned on the support screw to the desired paper width and the support screw turned to simultaneously position both guides until the type margin is at the desired location on the paper. The apparatus described by Euth et al. is relatively complicated and requires considerable operator time to effect adjustment.
The illustrated embodiment provides a web guide mechanism which is relatively simple in construction and may be quickly and accurately adjusted to acommodate various web widths and selected margin requirements. The apparatus described includes means for conveniently shifting the paper location with respect to the print mechanism so that the type margin on the paper may be accurately located without disturbing the web width setting. All adjustments may be accomplished quickly and the apparatus being relatively simple requires little or no maintenance.